To investigate the role of gut microbiota in E. coli O157 fecal shedding in cattle, 16S rRNA gene amplicon profiling was performed to characterize the mucosa associated microbiota of recto-anal junction of beef steers. Targeted loci

Cattle are the primary carrier of E. coli O157, which is a foodborne human pathogen, and the ones shedding > 4 log CFU/gram of feces of E. coli O157 were defined as super-shedder cattle (SS). The recto-anal junction (RAJ) is the primary colonization site of E. coli O157 in cattle. To date, the mechanisms of super-shedding remain unidentified. In this study, the amplicon sequencing of partial bacterial 16S rRNA gene was performed to characterize the mucosa associated microbiota at RAJ, and the profiles were compared between SS and fecal E. coli O157 free cattle (NS). Our findings suggest that difference in RAJ microbiota at both compositional and functional level may be associated with E. coli O157 super-shedding in beef steers.